From 16 to 12 to 14.5

[cnuttgirl]

I know that SUV's don't get the greatest mileage in the world, that's not why i bought my expy.
i have however noticed a significant drop in mpg since i have bought the truck. i bought the truck in january of '03 and got about 16mpg, one year later i was getting 12-13 mpg. keep in mind, this has been mostly highway driving (cause i know that in town driving really changes a lot compared to highway).

I have had the following done inthe following order:
new set of all weather tires

rear wiper motor

cruise control amplifier
rear hatch window seal

right side exhaust manifold
transmission dip stick tube
right side head gasket
transmission flush

K&N drop in air filter

front end ball joints
front end sway bar linkages
front end bushings

fuel filter

switched from using speedway gas staions to BP gas stations

oil additive engine cleaner (from auto-rx.com)

fuel injector cleaner (gum out's use every 3,000 miles brand)

i really noticed the truck running harder when i added the oil additive cleaner. soon as i changed the oil and put in new (and a new filter) it ran a little easier and the mpg went up to 13. after i added the fuel injector cleaner it's about 14.4 - 15.2.

to me, that still seems a little low compared to most people i hear getting 19 mpg on the highway. my mpg doesn't seem to fluxuate too badly between highway and in town.

is this an indication of something else that needs looked at...like should i be thinking about new plugs? i just rolled over 80K, and was going to wait until 100K to do plugs and flush my systems (radiator, tranny, transfer case and rear diff.).

any help would be greatly appreciated...cause i'm moving in two weeks and would like to do something simple before i start driving back and forth across the state hauling my stuff.

 

[Guest]

I get on average about 13, so your numbers sound about right. Mines a '00 xlt. Remeber, winter time driving will cause the mpg to drop. In alot of areas they use a different grade gas in the winter. I don't know about In. though.

 

[Fred69]

My 03 5.4 4x4 will get on a good day 14 MPG highway about 11 city. We have a winter blend of gas here in Mich. I use only Mobil mid grade... as I recall last summer It was avg of maybe + 1.5 Mpg highway, and + .5 city. Then again it's been a really low precipitation winter..... :-(

 

[cnuttgirl]

by the way, i forgot to add a couple of other things i have had done.

had new brakes put on the front end after the cruise control amp. was added.

I had the rear backing plates replaced while i was getting the front end suspension parts fixed.

after the suspension parts were replaced i went back for a "thunk" and decided to replace my drive shaft. i still have the "thunk"

i'm hoping that my loss in mgp was strictly due to winter blend gas (we get that here in IN too). I have about 13K left under my extended warranty, and if i can use it one more time for some tranny work i'd love it.

 

[bnvus]

MPG

CNUTTGIRL and all--

If you are watching the MPG indicator on the dash then keep in mind the average you are watching is the OVERALL MPG you have accrued since you have owned the truck. So basically the 14MPG you are seeing is the average of over a year...unless...you RESET it (with the button the dash or disconnected the battery). Once you do that, watch what your mileage says after a few miles. Bet you will be reading 16-17 MPG if you highway drive it then. Unfortunately it will once again creep back to the 14 average as miles accrue.

 

[Guest]

This post makes little to no sense so i can see now that ive read this, why youd be so defensive in regards to my post. IM really not trying to be a pain but how on earth have you done so many repairs to a 03'expedition. 19 mpg is kinda crazy , maybe from an 4.6 , and contrary to popular belief changing your wipers will not give you better gas mileage.

 

[rwinch]

I agree, 19 MPG can only be achieved by those lucky few who always are able to drive downhill.......both ways.

14.5-15 is the best I have ever got, and that is with pissed off people behind wondering why I am accelerating SLOWLY.

 

[PaulC]

2003 Expedition? The signature denotes a 1999.

Anyway, 80k? The plugs aren't too fresh, some benefit would be derived from a plug change. A clogged PCV valve will also hamper mileage, cheap to replace. Any recent additions to the exterior of the vehicle? Grill guards, bug deflectors, etc., will hamper mileage. Keeping the tires at the proper PSI?

If you are going to put the vehicle through its paces during the move, perhaps a sump full of Mobil One wouldn't be a bad idea.

It's unlikely that one change will/would dramatically affect mileage. Many small things add up.

 

[Texaskid05]

Bull pucky. I drove 535 miles from my town to Dallas a few weeks ago and got 19mpg on one tank and 21mpg on the other, I have over 70k miles on the beast,and no reason to fudge the numbers.
I'm not sure if people on here are jealous,,or just getting bad milage, But every truck is diffrent, I have 3:31 rear end gears, no 4x4 Maybe thats the dif, In town I am like most on here down in the 12-14 range. No reason to doubt someone elses milage claim though because I am sure if I had actually gone the speed limit my milage might have been better still.

 

[cnuttgirl]

"icehouse" again, not all reapairs listed were a direct link to reduced gas mileage, but some were (by the way it's a 99 model). I didn't have the wipers replaced I have the rear wiper motor replaced. and yes, i do realize that that doesn't effect gas mileage. But something like a better air filter might or a new fuel filter. If the air to fuel ratio is a fixed constant number, and you put a new/better air filter in that allows for better/cleaner/more air flow...by definition the gas useage has to go up (keep in mind that is only if the air fuel ratio is a constant...i don't know if it is or not.)

I had expected to see a little better (like 1-2 mpg increase) with teh better air filter and new fuel filter. I listed them to get feedback on what people thought on the type or brands of things that i listed. Maybe someone out there knows that K&N filters suck in expy's and could point me in another direction.

Maybe someone would notice something that i had done ask why and give me a better avenue for a better repair. My post (even though the thread title was named as such) did not pertain only to gas mileage problems. It was the main problem and main theme though.

you are right, in that i listed a lot of things that do not pertain to gas mileage detrement or improvement, but your reply was immature at best. if you don't want to help me or provide me with valuable information in the future then don't relpy to my future threads.

I really value people's opinions on this site. I have been helped 99% of the time...mainly in not getting screwed by dealers when i go in and ask a question about a rattle or a squeek. From this site I have been able to go to the dealer and provide more detail for them to be able to repair my truck.

for the rest of you reading this thread that have probably replied to me in the past, thank you so much for all of your help. My miles are almost out on my extended warranty, and absolutely everything that i have asked about on this forum was covered under my warranty terms. Again, THANKYOU very much for all of your help, and i look forward to more help in the future.

 

[cnuttgirl]

"paulC" i was really wondering about teh PCV valve as well as the mass air flow sensor. I have heard some people foul the sensor when the use K&N filters because after cleaning and reoiling excess oil coats the MAF. If you were to pull out the MAF what should it look like?? I mean is it unreasonable to expect it to look crystal clear?? If it is fouled, how do you clean it?? it's okay if you don't know the answers, but maybe if you don't know you could point me in another direction. thanks again for your reply it makes sense to me.

one last thing...where would i find the PCV?

 

[rwinch]

To clean the MAF check out this very detailed link...

http://www.fordscorpio.co.uk/cleanmaf.htm

In terms of the PCV valve, it is a snap to replace. First, go to your local auto parts store, and pick one up (they are not expensive). Open your hood and look to the left side valve cover, and right behind where you put in new motor oil is the port in which the PCV valve sits. Pull the valve out, and remove it from the return hose. Install the new unit in reverse order. The attached picture shows where this is located, as indicated by the find number "2".

Hope this helps!!

 

[rednvegas]

newbie here:0)
I own three Fords one of which is a F350 with the powerstroke, i installed a K&N drop in and lost mpg took the thing out and droped a Fram in and got the 3mpg back...hope it helps

the other two Fords are
01 Expy 4x4 EB
00 Mustang
I installed cat backs on the mustang and saw mpg increase so the expy is getting a cat back and C.A.I real soon.

 

[monsta]

cnuttgirl,

What is the true outer diameter of the new tires you installed versus the old tires.

You see, most tires, even though the same size, have difference true diameters.

This can create an illusion of reduced economy.

 

[cnuttgirl]

hmmmm, never thought of that. and those tires now have about 60K on them. i do have another set in the garage that i'll measure just to see the difference.

 

[monsta]

Best bet would be to go the manufacturer's webstie for each brand of tire and get the published "Revolutions per Mile".

My guess is that there would be a difference.

Now that the tires have worn you're seeing a rise in mileage again.

 

[pacpark4]

I put an K&N Filter in my 2000 Expy 5.4 4x4 and noticed a 1.5 drop in mpg. I put a Fram filter in and the mileage returned to normal levels. I only use 87 octane here in Washington State, and my Expy has never pinged. Cruising around 65 mph on the freeway, I average 16 mpg, but if I speed up to 70 it drops to 15.4 and at 75 mpg. around 15.1 mpg. In town, I average between 11.5 - 12.2. I don't have any modifications on my Expy but I do have the 3.55 rear axle.......Keep your foot out of it on the open road and hopefully you'll get another 50 miles out of a tank.

 

[Sanchez_315er]

80K? I'll bet on O2 sensors.

Don't forget that in colder temps, there is a denser air charge coming in, and therefore O2 sensors see it being lean.... and then they add more fuel... smart, huh? It was the exact opposite for my carbed vehicles... I got AWESOME mileage in winter.

Keep us posted.

 

[cnuttgirl]

well, now i'm at 116K. i'm getting ready to do all the fluids, plugs, and new belt. while i'm under there...i guess i'll take a look at the O2 sensors. i'm going to try a new air filter...True Flow. it's a foam filter, that you can "clean" by blowing compressed air through it. watched a video about it, where it was compared against a paper filter and a K&N type filter. this foam filter trapped more dirt and was easiest to clean.
here's the cheapest place i have found them so far:
http://www.autopartswarehouse.com/p...ear=1999&part=air_filter&part_brand=true_flow